Diffusers of the above-mentioned type are widely used in lighting devices, particularly luminaires, for modifying the light emitted by the light source of the lighting device.
US-2011/0267680 A1 describes an optical device comprising a deformable polymer film substrate and a rigid optical element, which in one embodiment is a diffusing structure, provided on the substrate. Electrodes are connected to the substrate in order to enable deformation of the substrate, which in turn enables the rigid optical element to be displaced in the plane of the substrate.
This optical device, however, has static properties which may not be altered after the fabrication process has been concluded. Therefore it is necessary to produce a wide range of different diffusers depending on the modification of light desired and the purpose to be fulfilled in different applications.